The following is a list of notes that have been reported as "Missing". Some of the notes have been lost in the postal system between sender and receipient, others have been stolen. If some of your notes have been lost in transit or stolen please send the details the IBNS Webmaster - webmaster@ibns.biz to get them added to this list.

Other innovative techniques included special ways of cutting the paper surrounding the printed surface of a banknote, applying script to the inside of the banknote, and in modern times, imbedding metal strips or threads in the paper – a process now employed in the currency of most countries. Some French Assignaughts were printed with printed selvages, which were then cut in a wavy pattern from the banknote, given the same serial number and filed. Suspicious banknotes could then be compared with the selvage on file to see if the printing on the selvage edge of a questionable banknote exactly mated with the printing on file to determine authenticity. A few other countries also used this technique. The Bank of England printed its pound-value banknotes in pairs, leaving three edges rough and one edge smooth. Different denominations had small, easily missed indents cut at selected points along the unfinished right or left edges.

Banknotes of Tibet, printed on paper hand-made from mulberry bark, were, in the paper-making process, when the paper was very thin, written upon, then layered with another thin sheet of paper, imprisoning the inscription within the paper. Held up to the sun or bright light, the inscription could be seen much like a watermark.

The next innovation in banknote making was the employment of elaborate engravings to further complicate their reproduction by would-be counterfeiters. This technology was brought to a high level in about 1840 by the American Banknote Company (ABC), which assembled teams of the best engravers of the time to hand-engrave banknote plates. Different engravers etched each part of a banknote, some specializing in portraits, while others engraved letters, numbers, etc., producing master plates used to make printing plates. Advanced for the time, a number of countries, including the United States, turned to the ABC to print their currency. Today, these banknotes, many of which are masterpieces of art in their own right, are highly regarded and sought after by collectors.

One engraving discovery to emerge in the early 19th century was the realization the faithful portrayal of human skin was extremely difficult – a skill mastered by few engravers. Exploiting the difficulty, despite the prudish mores of the time, many 19th century banknotes feature vignettes of nudes, presumably on the theory that the more skin the better. The Banque de France extensively employed the technique on French and colonial banknotes. The practice may have reached its peak on Finnish banknotes issued in the 1930s portraying happy groups of nudists.

Although outwitting counterfeiters was the primary objective behind printing advances, necessity was also a force. By the mid-19th century, paper money was becoming more acceptable to people as a media of exchange. Expanding commerce and the industrial revolution saw a commensurate leap in the size and volume of financial transactions. The amount of money needed could no longer be physically or safely carried through the streets. Nor was it practical to move coin in huge amounts from one depository to another. Paper money filled the gap! And, it had to be secure.